1.
Lite-Trac
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Lite-Trac is a trading name of Holme Farm Supplies Ltd, a manufacturer of agricultural machinery registered in England and based in Peterborough. Holme Farm Supplies Ltd agricultural products, sold under the Lite-Trac name, include tool carriers, self-propelled lime and fertiliser spreaders, sprayers, granular applicators, Lite-Trac is currently the manufacturer of Europes largest four-wheeled self-propelled crop sprayers. The companys products are identifiable by the combination of unpainted stainless steel tanks and booms with bright yellow cabs, Lite-Trac had existed as a name since before 2006, with first prototypes built in 2004. Following the success of initial testing, Lite-Trac was incorporated in 2008 to develop, since then Lite-Trac has gone on to develop its own crop sprayers which exploit the potential of the SS2400 chassis and has branched out into spreading and granular application. Lite-Trac manufactures a range of agricultural machinery, the Lite-Trac SS2400 is a tool carrier with a 14 tonne payload capacity. The patented chassis layout with its mid-mounted driveline gives equal weight distribution on all four wheels, the fully mechanical driveline is particularly suited to heavy work in hilly conditions and includes a 6 speed automatic power shift gearbox with locking torque converter which is capable of 50 km/h. It also features a 260 horse power engine, air suspension, anti-roll bars, when it comes to self-propelled sprayers, there is big and bigger. Then we come to the Lite Trac, agri-Spread high capacity demountable spreader mounts onto the SS2400 Tool Carrier and is specifically designed to take full advantage of its 50/50 weight distribution. The spreader is capable of spreading a wide range of materials including fertiliser, fibre foss, lime, the standard hopper can hold up to 12t lime, or 5. 6t fertiliser, and extension sides are available for lighter materials. Spreading widths of 24m and above are achievable at rates of 20 kg/Ha to 4t/Ha, Lite-Trac pneumatic applicators for precision application of slug pellets and Avadex are manufactured in widths of up to 36 metres. Harvest Highlights Photos 2010 Farmers Weekly ispace, view from the H-edge Farmers Weekly ispace. Official website Video of an earlier model in action
2.
Lime (material)
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Lime is a calcium-containing inorganic material in which carbonates, oxides, and hydroxides predominate. In the strict sense of the term, lime is calcium oxide or calcium hydroxide and it is also the name of the natural mineral CaO which occurs as a product of coal seam fires and in altered limestone xenoliths in volcanic ejecta. The word lime originates with its earliest use as building mortar and has the sense of sticking or adhering and these materials are still used in large quantities as building and engineering materials, as chemical feedstocks, and for sugar refining, among other uses. Lime industries and the use of many of the resulting products date from prehistoric times in both the Old World and the New World, Lime is used extensively for wastewater treatment with ferrous sulfate. The rocks and minerals from which these materials are derived, typically limestone or chalk, are composed primarily of calcium carbonate and they may be cut, crushed or pulverized and chemically altered. Lime kilns are the used for lime burning and slaking. When the term is encountered in a context, it usually refers to agricultural lime. Otherwise it most commonly means slaked lime, as the dangerous form is usually described more specifically as quicklime or burnt lime. In the lime industry, limestone is a term for rocks that contain 80% or more of calcium or magnesium carbonates, including marble, chalk, oolite. Further classification is by composition as high calcium, argillaceous, silicious, conglomerate, magnesian, dolomite, uncommon sources of lime include coral, sea shells, calcite, and ankerite. Limestone is extracted from quarries or mines, dry slaking is when quicklime is slaked with just enough water to hydrate the quicklime, but remain as a powder and is referred to as hydrated lime. In wet slaking, enough water, but not too much, is added to hydrate the quicklime to a referred to as lime putty. Because lime has a property with bricks and stones, it is often used as binding material in masonry works. It is also used in whitewashing as wall coat to adhere the whitewash onto the wall, the process by which limestone is converted to quicklime by heating, then to slaked lime by hydration, and naturally reverts to calcium carbonate by carbonation is called the lime cycle. The conditions and compounds present during each step of the cycle have a strong influence of the end product, thus the complex. An example is when slaked lime is mixed into a slurry with sand. When the masonry has been laid, the lime in the mortar slowly begins to react with carbon dioxide to form calcium carbonate according to the reaction. The carbon dioxide that takes part in reaction is principally available in the air or dissolved in rainwater so pure lime mortar will not recarbonate under water or inside a thick masonry wall
3.
American and British English spelling differences
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Many of the differences between American and British English date back to a time when spelling standards had not yet developed. For instance, some spellings seen as American today were once used in Britain. But English-language spelling reform has rarely been adopted otherwise, and thus modern English orthography varies somewhat between countries and is far from phonemic in any country, in the early 18th century, English spelling was inconsistent. These differences became noticeable after the publishing of influential dictionaries, todays British English spellings mostly follow Johnsons A Dictionary of the English Language, while many American English spellings follow Websters An American Dictionary of the English Language. Webster was a proponent of English spelling reform for reasons both philological and nationalistic, in A Companion to the American Revolution, John Algeo notes, it is often assumed that characteristically American spellings were invented by Noah Webster. He was very influential in popularizing certain spellings in America, rather he chose already existing options such as center, color and check for the simplicity, analogy or etymology. William Shakespeares first folios, for example, used spellings like center and color as much as centre, Webster did attempt to introduce some reformed spellings, as did the Simplified Spelling Board in the early 20th century, but most were not adopted. In Britain, the influence of those who preferred the Norman spellings of words proved to be decisive, later spelling adjustments in the United Kingdom had little effect on todays American spellings and vice versa. For the most part, the systems of most Commonwealth countries. Australian spelling has also strayed slightly from British spelling, with some American spellings incorporated as standard, New Zealand spelling is almost identical to British spelling, except in the word fiord. There is also an increasing use of macrons in words that originated in Māori, most words ending in an unstressed -our in British English end in -or in American English. Wherever the vowel is unreduced in pronunciation, e. g. contour, velour, paramour and troubadour the spelling is the same everywhere, most words of this kind came from Latin, where the ending was spelled -or. They were first adopted into English from early Old French, after the Norman conquest of England, the ending became -our to match the Old French spelling. The -our ending was not only used in new English borrowings, however, -or was still sometimes found, and the first three folios of Shakespeares plays used both spellings before they were standardised to -our in the Fourth Folio of 1685. After the Renaissance, new borrowings from Latin were taken up with their original -or ending, Websters 1828 dictionary had only -or and is given much of the credit for the adoption of this form in the United States. Johnson, unlike Webster, was not an advocate of spelling reform and he preferred French over Latin spellings because, as he put it, the French generally supplied us. In Jeffersons original draft it is spelled honour, Honor and honour were equally frequent in Britain until the 17th century, honor still is, in the UK, the usual spelling as a persons name and appears in Honor Oak, a district of London. In derivatives and inflected forms of the words, British usage depends on the nature of the suffix used
4.
Liming (soil)
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Liming is the application of calcium- and magnesium-rich materials to soil in various forms, including marl, chalk, limestone, or hydrated lime. This neutralises soil acidity and increases activity of soil bacteria, however, oversupply may result in harm to plant life. Lime is a chemical, the effect of it makes the soil more basic thus making acidic soils neutral. The degree to which an amount of lime per unit of soil volume will increase soil pH depends on the cation exchange capacity. Soils with low CEC will show a more marked pH increase than soils with high CEC, but the low-CEC soils will witness more rapid leaching of the added bases, and so will see a quicker return to original acidity unless additional liming is done. Over-liming is most likely to occur on soil which has low CEC, such as sand which is deficient in buffering agents such as organic matter, most acid soils are saturated with aluminium rather than hydrogen ions. The acidity of the soil is therefore a result of hydrolysis of aluminium, alkali soils Soil conservation Soil pH Agricultural lime Aluminium Md Sanaul islam, khuna university A Study of the Lime Potential, R. C. Turner, Research Branch, Department Of Agriculture,1965
5.
Plant nutrition
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Plant nutrition is the study of the chemical elements and compounds necessary for plant growth, plant metabolism and their external supply. In 1972, Emanuel Epstein defined two criteria for an element to be essential for plant growth, in its absence the plant is unable to complete a life cycle. Or that the element is part of essential plant constituent or metabolite. This is in accordance with Justus von Liebigs law of the minimum, the essential plant nutrients include carbon, oxygen and hydrogen which are absorbed from the air, whereas other nutrients including nitrogen are typically obtained from the soil. And cobalt The macronutrients are consumed in larger quantities for Hydrogen, Oxygen, Nitrogen, micronutrients are present in plant tissue in quantities measured in parts per million, ranging from 0.1 to 200 ppm, or less than 0. 02% dry weight. Most soil conditions across the world can provide plants adapted to climate and soil with sufficient nutrition for a complete life cycle. However, if the soil is cropped it is necessary to artificially modify soil fertility through the addition of fertilizer to promote vigorous growth and this is done because, even with adequate water and light, nutrient deficiency can limit growth and crop yield. Plants take up essential elements from the soil through their roots, nutrient uptake in the soil is achieved by cation exchange, wherein root hairs pump hydrogen ions into the soil through proton pumps. These hydrogen ions displace cations attached to negatively charged particles so that the cations are available for uptake by the root. In the leaves, stomata open to take in carbon dioxide, the carbon dioxide molecules are used as the carbon source in photosynthesis. The root, especially the hair, is the essential organ for the uptake of nutrients. The structure and architecture of the root can alter the rate of nutrient uptake, nutrient ions are transported to the center of the root, the stele in order for the nutrients to reach the conducting tissues, xylem and phloem. The Casparian strip, a wall outside the stele but within the root, prevents passive flow of water and nutrients, helping to regulate the uptake of nutrients. Xylem moves water and inorganic molecules within the plant and phloem accounts for organic molecule transportation, water potential plays a key role in a plants nutrient uptake. Facilitated diffusion is the movement of solutes or ions following a concentration gradient. Nutrients can be moved within plants to where they are most needed, for example, a plant will try to supply more nutrients to its younger leaves than to its older ones. When nutrients are mobile within the plant, symptoms of any deficiency become apparent first on the older leaves, however, not all nutrients are equally mobile. Nitrogen, phosphorus, and potassium are mobile nutrients while the others have varying degrees of mobility, when a less-mobile nutrient is deficient, the younger leaves suffer because the nutrient does not move up to them but stays in the older leaves
6.
Plant
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Plants are mainly multicellular, predominantly photosynthetic eukaryotes of the kingdom Plantae. The term is generally limited to the green plants, which form an unranked clade Viridiplantae. This includes the plants, conifers and other gymnosperms, ferns, clubmosses, hornworts, liverworts, mosses and the green algae. Green plants have cell walls containing cellulose and obtain most of their energy from sunlight via photosynthesis by primary chloroplasts and their chloroplasts contain chlorophylls a and b, which gives them their green color. Some plants are parasitic and have lost the ability to produce amounts of chlorophyll or to photosynthesize. Plants are characterized by sexual reproduction and alternation of generations, although reproduction is also common. There are about 300–315 thousand species of plants, of which the great majority, green plants provide most of the worlds molecular oxygen and are the basis of most of Earths ecologies, especially on land. Plants that produce grains, fruits and vegetables form humankinds basic foodstuffs, Plants play many roles in culture. They are used as ornaments and, until recently and in variety, they have served as the source of most medicines. The scientific study of plants is known as botany, a branch of biology, Plants are one of the two groups into which all living things were traditionally divided, the other is animals. The division goes back at least as far as Aristotle, who distinguished between plants, which generally do not move, and animals, which often are mobile to catch their food. Much later, when Linnaeus created the basis of the system of scientific classification. Since then, it has become clear that the plant kingdom as originally defined included several unrelated groups, however, these organisms are still often considered plants, particularly in popular contexts. When the name Plantae or plant is applied to a group of organisms or taxon. The evolutionary history of plants is not yet settled. Those which have been called plants are in bold, the way in which the groups of green algae are combined and named varies considerably between authors. Algae comprise several different groups of organisms which produce energy through photosynthesis, most conspicuous among the algae are the seaweeds, multicellular algae that may roughly resemble land plants, but are classified among the brown, red and green algae. Each of these groups also includes various microscopic and single-celled organisms
7.
Proportionality (mathematics)
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In mathematics, two variables are proportional if a change in one is always accompanied by a change in the other, and if the changes are always related by use of a constant multiplier. The constant is called the coefficient of proportionality or proportionality constant, if one variable is always the product of the other and a constant, the two are said to be directly proportional. X and y are directly proportional if the ratio y/x is constant, if the product of the two variables is always a constant, the two are said to be inversely proportional. X and y are inversely proportional if the product xy is constant, to express the statement y is directly proportional to x mathematically, we write an equation y = cx, where c is the proportionality constant. Symbolically, this is written as y ∝ x, to express the statement y is inversely proportional to x mathematically, we write an equation y = c/x. We can equivalently write y is proportional to 1/x. An equality of two ratios is called a proportion, for example, a/c = b/d, where no term is zero. Given two variables x and y, y is proportional to x if there is a non-zero constant k such that y = k x. The relation is denoted, using the ∝ or ~ symbol, as y ∝ x. If an object travels at a constant speed, then the distance traveled is directly proportional to the time spent traveling, the circumference of a circle is directly proportional to its diameter, with the constant of proportionality equal to π. Since y = k x is equivalent to x = y, it follows that if y is proportional to x, with proportionality constant k. The concept of inverse proportionality can be contrasted against direct proportionality, consider two variables said to be inversely proportional to each other. If all other variables are constant, the magnitude or absolute value of one inversely proportional variable decreases if the other variable increases. Formally, two variables are proportional if each of the variables is directly proportional to the multiplicative inverse of the other. As an example, the time taken for a journey is inversely proportional to the speed of travel, the graph of two variables varying inversely on the Cartesian coordinate plane is a rectangular hyperbola. The product of the x and y values of each point on the curve equals the constant of proportionality, since neither x nor y can equal zero, the graph never crosses either axis. A variable y is proportional to a variable x, if y is directly proportional to the exponential function of x, that is if there exist non-zero constants k. Likewise, a y is logarithmically proportional to a variable x, if y is directly proportional to the logarithm of x, that is if there exist non-zero constants k
8.
Nitrogen
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Nitrogen is a chemical element with symbol N and atomic number 7. It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772, although Carl Wilhelm Scheele and Henry Cavendish had independently done so at about the same time, Rutherford is generally accorded the credit because his work was published first. Nitrogen is the lightest member of group 15 of the periodic table, the name comes from the Greek πνίγειν to choke, directly referencing nitrogens asphyxiating properties. It is an element in the universe, estimated at about seventh in total abundance in the Milky Way. At standard temperature and pressure, two atoms of the element bind to form dinitrogen, a colourless and odorless diatomic gas with the formula N2, dinitrogen forms about 78% of Earths atmosphere, making it the most abundant uncombined element. Nitrogen occurs in all organisms, primarily in amino acids, in the nucleic acids, the human body contains about 3% nitrogen by mass, the fourth most abundant element in the body after oxygen, carbon, and hydrogen. The nitrogen cycle describes movement of the element from the air, into the biosphere and organic compounds, many industrially important compounds, such as ammonia, nitric acid, organic nitrates, and cyanides, contain nitrogen. The extremely strong bond in elemental nitrogen, the second strongest bond in any diatomic molecule. Synthetically produced ammonia and nitrates are key industrial fertilisers, and fertiliser nitrates are key pollutants in the eutrophication of water systems. Apart from its use in fertilisers and energy-stores, nitrogen is a constituent of organic compounds as diverse as Kevlar used in high-strength fabric, Nitrogen is a constituent of every major pharmacological drug class, including antibiotics. Many notable nitrogen-containing drugs, such as the caffeine and morphine or the synthetic amphetamines. Nitrogen compounds have a long history, ammonium chloride having been known to Herodotus. They were well known by the Middle Ages, alchemists knew nitric acid as aqua fortis, as well as other nitrogen compounds such as ammonium salts and nitrate salts. The mixture of nitric and hydrochloric acids was known as aqua regia, celebrated for its ability to dissolve gold, the discovery of nitrogen is attributed to the Scottish physician Daniel Rutherford in 1772, who called it noxious air. Though he did not recognise it as a different chemical substance, he clearly distinguished it from Joseph Blacks fixed air. The fact that there was a component of air that does not support combustion was clear to Rutherford, Nitrogen was also studied at about the same time by Carl Wilhelm Scheele, Henry Cavendish, and Joseph Priestley, who referred to it as burnt air or phlogisticated air. Nitrogen gas was inert enough that Antoine Lavoisier referred to it as air or azote, from the Greek word άζωτικός. In an atmosphere of nitrogen, animals died and flames were extinguished
9.
Phosphorus
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Phosphorus is a chemical element with symbol P and atomic number 15. As an element, phosphorus exists in two major forms—white phosphorus and red phosphorus—but because it is reactive, phosphorus is never found as a free element on Earth. At 0. 099%, phosphorus is the most abundant pnictogen in the Earths crust, with few exceptions, minerals containing phosphorus are in the maximally oxidised state as inorganic phosphate rocks. The glow of phosphorus itself originates from oxidation of the white phosphorus — a process now termed chemiluminescence, together with nitrogen, arsenic, antimony, and bismuth, phosphorus is classified as a pnictogen. Phosphates are a component of DNA, RNA, ATP, and the phospholipids, demonstrating the link between phosphorus and life, elemental phosphorus was first isolated from human urine, and bone ash was an important early phosphate source. Phosphate mines contain fossils, especially marine fossils, because phosphate is present in the deposits of animal remains. Low phosphate levels are an important limit to growth in aquatic systems. The vast majority of compounds produced are consumed as fertilisers. Phosphate is needed to replace the phosphorus that plants remove from the soil, other applications include the role of organophosphorus compounds in detergents, pesticides, and nerve agents. Phosphorus exists as several forms that exhibit different properties. The two most common allotropes are white phosphorus and red phosphorus, from the perspective of applications and chemical literature, the most important form of elemental phosphorus is white phosphorus, often abbreviated as WP. It is a soft and waxy solid consists of tetrahedral P4 molecules. This P4 tetrahedron is also present in liquid and gaseous phosphorus up to the temperature of 800 °C when it starts decomposing to P2 molecules, White phosphorus exists in two crystalline forms, α and β. At room temperature, the α-form is stable, which is common and it has cubic crystal structure and at 195.2 K, it transforms into β-form. These forms differ in terms of the orientations of the constituent P4 tetrahedra. White phosphorus is the least stable, the most reactive, the most volatile, the least dense, White phosphorus gradually changes to red phosphorus. This transformation is accelerated by light and heat, and samples of white phosphorus almost always some red phosphorus. For this reason, white phosphorus that is aged or otherwise impure is also called yellow phosphorus, when exposed to oxygen, white phosphorus glows in the dark with a very faint tinge of green and blue
10.
Potassium
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Potassium is a chemical element with symbol K and atomic number 19. It was first isolated from potash, the ashes of plants, in the periodic table, potassium is one of the alkali metals. Potassium in nature only in ionic salts. It is found dissolved in sea water, and is part of many minerals, naturally occurring potassium is composed of three isotopes, of which 40K is radioactive. Traces of 40K are found in all potassium, and it is the most common radioisotope in the human body, Potassium is chemically very similar to sodium, the previous element in Group 1 of the periodic table. They have a similar energy, which allows for each atom to give up its sole outer electron. That they are different elements combine with the same anions to make similar salts was suspected in 1702. Most industrial applications of potassium exploit the high solubility in water of potassium compounds, heavy crop production rapidly depletes the soil of potassium, and this can be remedied with agricultural fertilizers containing potassium, accounting for 95% of global potassium chemical production. Potassium ions are necessary for the function of all living cells, fresh fruits and vegetables are good dietary sources of potassium. Potassium is the second least dense metal after lithium and it is a soft solid with a low melting point, and can be easily cut with a knife. Freshly cut potassium is silvery in appearance, but it begins to tarnish toward gray immediately on exposure to air, in a flame test, potassium and its compounds emit a lilac color with a peak emission wavelength of 766.5 nanometers. Neutral potassium atoms have 19 electrons, one more than the stable configuration of the noble gas argon. This process requires so little energy that potassium is readily oxidized by atmospheric oxygen, in contrast, the second ionization energy is very high, because removal of two electrons breaks the stable noble gas electronic configuration. Potassium therefore does not readily form compounds with the state of +2 or higher. Potassium is an active metal that reacts violently with oxygen in water. With oxygen it forms potassium peroxide, and with water potassium forms potassium hydroxide, the reaction of potassium with water is dangerous because of its violent exothermic character and the production of hydrogen gas. Hydrogen reacts again with atmospheric oxygen, producing water, which reacts with the remaining potassium and this reaction requires only traces of water, because of this, potassium and the liquid sodium-potassium — NaK — are potent desiccants that can be used to dry solvents prior to distillation. Because of the sensitivity of potassium to water and air, reactions with other elements are only in an inert atmosphere such as argon gas using air-free techniques
11.
Calcium
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Calcium is a chemical element with symbol Ca and atomic number 20. Calcium is a soft grayish-yellow alkaline earth metal, fifth-most-abundant element by mass in the Earths crust, the ion Ca2+ is also the fifth-most-abundant dissolved ion in seawater by both molarity and mass, after sodium, chloride, magnesium, and sulfate. Free calcium metal is too reactive to occur in nature, Calcium is produced in supernova nucleosynthesis. Calcium is a trace element in living organisms. It is the most abundant metal by mass in animals, and it is an important constituent of bone, teeth. In cell biology, the movement of the calcium ion into, Calcium carbonate and calcium citrate are often taken as dietary supplements. Calcium is on the World Health Organizations List of Essential Medicines, Calcium has a wide variety of applications, almost all of which are associated with calcium compounds and salts. Calcium metal is used as a deoxidizer, desulfurizer, and decarbonizer for production of ferrous and nonferrous alloys. In steelmaking and production of iron, Ca reacts with oxygen, Calcium carbonate is used in manufacturing cement and mortar, lime, limestone and aids in production in the glass industry. It also has chemical and optical uses as mineral specimens in toothpastes, Calcium hydroxide solution is used to detect the presence of carbon dioxide in a gas sample bubbled through a solution. The solution turns cloudy where CO2 is present, Calcium arsenate is used in insecticides. Calcium carbide is used to make acetylene gas and various plastics, Calcium chloride is used in ice removal and dust control on dirt roads, as a conditioner for concrete, as an additive in canned tomatoes, and to provide body for automobile tires. Calcium citrate is used as a food preservative, Calcium cyclamate is used as a sweetening agent in several countries. In the United States, it has been outlawed as a suspected carcinogen, Calcium gluconate is used as a food additive and in vitamin pills. Calcium hypochlorite is used as a swimming pool disinfectant, as an agent, as an ingredient in deodorant. Calcium permanganate is used in rocket propellant, textile production, as a water sterilizing agent. Calcium phosphate is used as a supplement for animal feed, fertilizer, in production for dough and yeast products, in the manufacture of glass. Calcium phosphide is used in fireworks, rodenticide, torpedoes, Calcium sulfate is used as common blackboard chalk, as well as, in its hemihydrate form, Plaster of Paris
12.
Magnesium
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Magnesium is a chemical element with symbol Mg and atomic number 12. Magnesium is the ninth most abundant element in the universe and it is produced in large, aging stars from the sequential addition of three helium nuclei to a carbon nucleus. When such stars explode as supernovas, much of the magnesium is expelled into the medium where it may recycle into new star systems. Magnesium is the eighth most abundant element in the Earths crust and the fourth most common element in the Earth, making up 13% of the planets mass and it is the third most abundant element dissolved in seawater, after sodium and chlorine. Magnesium occurs naturally only in combination with elements, where it invariably has a +2 oxidation state. The free element can be produced artificially, and is highly reactive, the free metal burns with a characteristic brilliant-white light. The metal is now obtained mainly by electrolysis of magnesium salts obtained from brine, Magnesium is less dense than aluminium, and the alloy is prized for its combination of lightness and strength. Magnesium is the eleventh most abundant element by mass in the body and is essential to all cells. Magnesium ions interact with polyphosphate compounds such as ATP, DNA, hundreds of enzymes require magnesium ions to function. Magnesium compounds are used medicinally as common laxatives, antacids, elemental magnesium is a gray-white lightweight metal, two-thirds the density of aluminium. Magnesium has the lowest melting and the lowest boiling point 1,363 K of all the alkaline earth metals, Magnesium reacts with water at room temperature, though it reacts much more slowly than calcium, a similar group 2 metal. When submerged in water, hydrogen bubbles form slowly on the surface of the metal—though, if powdered, the reaction occurs faster with higher temperatures. Magnesiums reversible reaction with water can be harnessed to store energy, Magnesium also reacts exothermically with most acids such as hydrochloric acid, producing the metal chloride and hydrogen gas, similar to the HCl reaction with aluminium, zinc, and many other metals. Magnesium is highly flammable, especially when powdered or shaved into thin strips, flame temperatures of magnesium and magnesium alloys can reach 3,100 °C, although flame height above the burning metal is usually less than 300 mm. Once ignited, such fires are difficult to extinguish, with combustion continuing in nitrogen, carbon dioxide, Magnesium may also be used as an igniter for thermite, a mixture of aluminium and iron oxide powder that ignites only at a very high temperature. When burning in air, magnesium produces a light that includes strong ultraviolet wavelengths. Magnesium powder was used for illumination in the early days of photography. Later, magnesium filament was used in electrically ignited single-use photography flashbulbs, Magnesium powder is used in fireworks and marine flares where a brilliant white light is required
13.
Sulfur
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Sulfur or sulphur is a chemical element with symbol S and atomic number 16. It is abundant, multivalent, and nonmetallic, under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a yellow crystalline solid at room temperature. Chemically, sulfur reacts with all elements except for gold, platinum, iridium, tellurium, though sometimes found in pure, native form, sulfur usually occurs as sulfide and sulfate minerals. Being abundant in native form, sulfur was known in ancient times, being mentioned for its uses in ancient India, ancient Greece, China, in the Bible, sulfur is called brimstone. Today, almost all elemental sulfur is produced as a byproduct of removing sulfur-containing contaminants from natural gas, the greatest commercial use of the element is the production of sulfuric acid for sulfate and phosphate fertilizers, and other chemical processes. The element sulfur is used in matches, insecticides, and fungicides, many sulfur compounds are odoriferous, and the smells of odorized natural gas, skunk scent, grapefruit, and garlic are due to organosulfur compounds. Hydrogen sulfide gives the characteristic odor to rotting eggs and other biological processes, sulfur is an essential element for all life, but almost always in the form of organosulfur compounds or metal sulfides. Three amino acids and two vitamins are organosulfur compounds, many cofactors also contain sulfur including glutathione and thioredoxin and iron–sulfur proteins. Disulfides, S–S bonds, confer mechanical strength and insolubility of the keratin, found in outer skin, hair. Sulfur is one of the chemical elements needed for biochemical functioning and is an elemental macronutrient for all organisms. Sulfur is derived from the Latin word sulpur, which was Hellenized to sulphur, the spelling sulfur appears toward the end of the Classical period. In 12th-century Anglo-French, it was sulfre, in the 14th century the Latin ph was restored, for sulphre, the parallel f~ph spellings continued in Britain until the 19th century, when the word was standardized as sulphur. Sulfur was the form chosen in the United States, whereas Canada uses both, the IUPAC adopted the spelling sulfur in 1990, as did the Nomenclature Committee of the Royal Society of Chemistry in 1992, restoring the spelling sulfur to Britain. Sulfur forms polyatomic molecules with different chemical formulas, the best-known allotrope being octasulfur, cyclo-S8. The point group of cyclo-S8 is D4d and its dipole moment is 0 D. Octasulfur is a soft, bright-yellow solid that is odorless and it melts at 115.21 °C, boils at 444.6 °C and sublimes easily. At 95.2 °C, below its melting temperature, cyclo-octasulfur changes from α-octasulfur to the β-polymorph, the structure of the S8 ring is virtually unchanged by this phase change, which affects the intermolecular interactions. At higher temperatures, the viscosity decreases as depolymerization occurs, molten sulfur assumes a dark red color above 200 °C
14.
Copper
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Copper is a chemical element with symbol Cu and atomic number 29. It is a soft, malleable, and ductile metal with high thermal and electrical conductivity. A freshly exposed surface of copper has a reddish-orange color. Copper is one of the few metals that occur in nature in directly usable metallic form as opposed to needing extraction from an ore and this led to very early human use, from c.8000 BC. Copper used in buildings, usually for roofing, oxidizes to form a green verdigris, Copper is sometimes used in decorative art, both in its elemental metal form and in compounds as pigments. Copper compounds are used as agents, fungicides, and wood preservatives. Copper is essential to all living organisms as a trace dietary mineral because it is a key constituent of the enzyme complex cytochrome c oxidase. In molluscs and crustaceans, copper is a constituent of the blood pigment hemocyanin, replaced by the hemoglobin in fish. In humans, copper is found mainly in the liver, muscle, the adult body contains between 1.4 and 2.1 mg of copper per kilogram of body weight. The filled d-shells in these elements contribute little to interatomic interactions, unlike metals with incomplete d-shells, metallic bonds in copper are lacking a covalent character and are relatively weak. This observation explains the low hardness and high ductility of single crystals of copper, at the macroscopic scale, introduction of extended defects to the crystal lattice, such as grain boundaries, hinders flow of the material under applied stress, thereby increasing its hardness. For this reason, copper is supplied in a fine-grained polycrystalline form. The softness of copper partly explains its high conductivity and high thermal conductivity. The maximum permissible current density of copper in open air is approximately 3. 1×106 A/m2 of cross-sectional area, Copper is one of a few metallic elements with a natural color other than gray or silver. Pure copper is orange-red and acquires a reddish tarnish when exposed to air, as with other metals, if copper is put in contact with another metal, galvanic corrosion will occur. A green layer of verdigris can often be seen on old structures, such as the roofing of many older buildings. Copper tarnishes when exposed to sulfur compounds, with which it reacts to form various copper sulfides. There are 29 isotopes of copper, 63Cu and 65Cu are stable, with 63Cu comprising approximately 69% of naturally occurring copper, both have a spin of 3⁄2
15.
Iron fertilization
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Iron fertilization is the intentional introduction of iron to the upper ocean to stimulate a phytoplankton bloom. This is intended to enhance productivity, which can benefit the marine food chain and is under investigation in hopes of increasing carbon dioxide removal from the atmosphere. Iron is an element necessary for photosynthesis in all plants. It is highly insoluble in sea water and is often the limiting nutrient for phytoplankton growth, large algal blooms can be created by supplying iron to iron-deficient ocean waters. Since 1993, thirteen international research teams have completed ocean trials demonstrating that phytoplankton blooms can be stimulated by iron addition, however, controversy remains over the effectiveness of atmospheric CO2 sequestration and ecological effects. Fertilization also occurs naturally when upwellings bring nutrient-rich water to the surface and this form of fertilization produces the worlds largest marine habitats. Fertilization can also occur when weather carries wind blown dust long distances over the ocean, or iron-rich minerals are carried into the ocean by glaciers, rivers and icebergs. Little further scientific discussion of issue was recorded until the 1980s. Perhaps the most dramatic support for Martins hypothesis was seen in the aftermath of the 1991 eruption of Mount Pinatubo in the Philippines, environmental scientist Andrew Watson analyzed global data from that eruption and calculated that it deposited approximately 40,000 tons of iron dust into the oceans worldwide. This single fertilization event generated an easily observed global decline in atmospheric CO2, the parties to the London Dumping Convention adopted a non-binding resolution in 2008 on fertilization. An Assessment Framework for Scientific Research Involving Ocean Fertilization, regulating the dumping of wastes at sea was adopted by the Contracting Parties to the Convention in October 2010. Martin hypothesized that increasing phytoplankton photosynthesis could slow or even global warming by sequestering enormous volumes of CO2 in the sea. In contrast to the LOHAFEX experiment, also conducted in a mesoscale eddy, CROZEX,2005 One pilot project planned by Planktos, a U. S. company, was cancelled in 2008 for lack of funding. The company blamed environmental organizations for the failure, LOHAFEX,2009 Despite widespread opposition to LOHAFEX, on 26 January 2009 the German Federal Ministry of Education and Research gave clearance for this fertilization experiment to commence. The experiment was carried out in low in silicic acid which is likely to affect the efficacy of carbon sequestration. A900 square kilometers portion of the southwest Atlantic Ocean was fertilized with iron sulfate, a large phytoplankton bloom was triggered, however this bloom did not contain diatoms because the fertilized location was already depleted in silicic acid, an essential nutrient for diatom growth. In the absence of diatoms, a small amount of carbon was sequestered, because other phytoplankton are vulnerable to predation by zooplankton. These poor sequestration results have caused some to suggest that ocean iron fertilization is not an effective carbon mitigation strategy in general, however, prior ocean fertilization experiments in high silica locations have observed much higher carbon sequestration rates because of diatom growth
16.
Manganese
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Manganese is a chemical element with symbol Mn and atomic number 25. It is not found as an element in nature, it is often found in minerals in combination with iron. Manganese is a metal with important industrial metal alloy uses, particularly in stainless steels, by the mid-18th century, Swedish chemist Carl Wilhelm Scheele had used pyrolusite to produce chlorine. Scheele and others were aware that pyrolusite contained a new element, johan Gottlieb Gahn was the first to isolate an impure sample of manganese metal in 1774, which he did by reducing the dioxide with carbon. Manganese phosphating is used for rust and corrosion prevention on steel, ionized manganese is used industrially as pigments of various colors, which depend on the oxidation state of the ions. The permanganates of alkali and alkaline earth metals are powerful oxidizers, Manganese dioxide is used as the cathode material in zinc-carbon and alkaline batteries. In biology, manganese ions function as cofactors for a variety of enzymes with many functions. Manganese enzymes are essential in detoxification of superoxide free radicals in organisms that must deal with elemental oxygen. Manganese also functions in the complex of photosynthetic plants. The element is a trace mineral for all known living organisms but is a neurotoxin. In larger amounts, and apparently with far greater effectiveness through inhalation, Manganese is a silvery-gray metal that resembles iron. It is hard and very brittle, difficult to fuse, Manganese metal and its common ions are paramagnetic. Manganese tarnishes slowly in air and oxidizes like iron in water containing dissolved oxygen, naturally occurring manganese is composed of one stable isotope, 55Mn. Eighteen radioisotopes have been isolated and described, the most stable being 53Mn with a half-life of 3.7 million years, 54Mn with a half-life of 312.3 days, and 52Mn with a half-life of 5.591 days. All of the radioactive isotopes have half-lives of less than three hours, and the majority of less than one minute. Manganese also has three meta states, Manganese is part of the iron group of elements, which are thought to be synthesized in large stars shortly before the supernova explosion. 53Mn decays to 53Cr with a half-life of 3.7 million years, because of its relatively short half-life, 53Mn is relatively rare, produced by cosmic rays impact on iron. Manganese isotopic contents are combined with chromium isotopic contents and have found application in isotope geology
17.
Molybdenum
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Molybdenum is a chemical element with symbol Mo and atomic number 42. The name is from Neo-Latin molybdaenum, from Ancient Greek Μόλυβδος molybdos, meaning lead, molybdenum minerals have been known throughout history, but the element was discovered in 1778 by Carl Wilhelm Scheele. The metal was first isolated in 1781 by Peter Jacob Hjelm, molybdenum does not occur naturally as a free metal on Earth, it is found only in various oxidation states in minerals. The free element, a metal with a gray cast, has the sixth-highest melting point of any element. It readily forms hard, stable carbides in alloys, and for this reason most of production of the element is used in steel alloys. Most molybdenum compounds have low solubility in water, but when molybdenum-bearing minerals contact oxygen and water, industrially, molybdenum compounds are used in high-pressure and high-temperature applications as pigments and catalysts. Molybdenum-bearing enzymes are by far the most common catalysts for breaking the chemical bond in atmospheric molecular nitrogen in the process of biological nitrogen fixation. At least 50 molybdenum enzymes are now known in bacteria and animals and these nitrogenases contain molybdenum in a form different from other molybdenum enzymes, which all contain fully oxidized molybdenum in a molybdenum cofactor. These various molybdenum cofactor enzymes are vital to the organisms, and molybdenum is an element for life in all higher eukaryote organisms. In its pure form, molybdenum is a metal with a Mohs hardness of 5.5. It has a point of 2,623 °C, of the naturally occurring elements, only tantalum, osmium, rhenium, tungsten. Weak oxidation of molybdenum starts at 300 °C and it has one of the lowest coefficients of thermal expansion among commercially used metals. The tensile strength of molybdenum wires increases about 3 times, from about 10 to 30 GPa, there are 35 known isotopes of molybdenum, ranging in atomic mass from 83 to 117, as well as four metastable nuclear isomers. Seven isotopes occur naturally, with masses of 92,94,95,96,97,98. Of these naturally occurring isotopes, only molybdenum-100 is unstable, molybdenum-98 is the most abundant isotope, comprising 24. 14% of all molybdenum. Molybdenum-100 has a half-life of about 1019 y and undergoes double beta decay into ruthenium-100, molybdenum isotopes with mass numbers from 111 to 117 all have half-lives of approximately 150 ns. All unstable isotopes of molybdenum decay into isotopes of niobium, technetium, as also noted below, the most common isotopic molybdenum application involves molybdenum-99, which is a fission product. It is a parent radioisotope to the short-lived gamma-emitting daughter radioisotope technetium-99m, in 2008, the Delft University of Technology applied for a patent on the molybdenum-98-based production of molybdenum-99
18.
Zinc
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Zinc is a chemical element with the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table, in some respects zinc is chemically similar to magnesium, both elements exhibit only one normal oxidation state, and the Zn2+ and Mg2+ ions are of similar size. Zinc is the 24th most abundant element in Earths crust and has five stable isotopes, the most common zinc ore is sphalerite, a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States, Zinc is refined by froth flotation of the ore, roasting, and final extraction using electricity. Zinc metal was not produced on a large scale until the 12th century in India and was unknown to Europe until the end of the 16th century, the mines of Rajasthan have given definite evidence of zinc production going back to the 6th century BC. To date, the oldest evidence of pure zinc comes from Zawar, in Rajasthan, alchemists burned zinc in air to form what they called philosophers wool or white snow. The element was named by the alchemist Paracelsus after the German word Zinke. German chemist Andreas Sigismund Marggraf is credited with discovering pure metallic zinc in 1746, work by Luigi Galvani and Alessandro Volta uncovered the electrochemical properties of zinc by 1800. Corrosion-resistant zinc plating of iron is the application for zinc. Other applications are in batteries, small non-structural castings. A variety of compounds are commonly used, such as zinc carbonate and zinc gluconate, zinc chloride, zinc pyrithione, zinc sulfide. Zinc is an essential mineral perceived by the public today as being of exceptional biologic and public health importance, Zinc deficiency affects about two billion people in the developing world and is associated with many diseases. In children, deficiency causes growth retardation, delayed sexual maturation, infection susceptibility, enzymes with a zinc atom in the reactive center are widespread in biochemistry, such as alcohol dehydrogenase in humans. Consumption of excess zinc can cause ataxia, lethargy and copper deficiency, Zinc is a bluish-white, lustrous, diamagnetic metal, though most common commercial grades of the metal have a dull finish.6 pm. The metal is hard and brittle at most temperatures but becomes malleable between 100 and 150 °C, above 210 °C, the metal becomes brittle again and can be pulverized by beating. Zinc is a conductor of electricity. For a metal, zinc has relatively low melting and boiling points, the melting point is the lowest of all the transition metals aside from mercury and cadmium. Many alloys contain zinc, including brass, Other metals long known to form binary alloys with zinc are aluminium, antimony, bismuth, gold, iron, lead, mercury, silver, tin, magnesium, cobalt, nickel, tellurium, and sodium
19.
Boron
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Boron is a chemical element with symbol B and atomic number 5. Produced entirely by cosmic ray spallation and supernovae and not by stellar nucleosynthesis, it is an element in the Solar system. Boron is concentrated on Earth by the water-solubility of its more common naturally occurring compounds and these are mined industrially as evaporites, such as borax and kernite. The largest known deposits are in Turkey, the largest producer of boron minerals. Elemental boron is a metalloid that is found in small amounts in meteoroids, industrially, very pure boron is produced with difficulty because of refractory contamination by carbon or other elements. Several allotropes of boron exist, amorphous boron is a powder, crystalline boron is silvery to black, extremely hard. The primary use of boron is as boron filaments with applications similar to carbon fibers in some high-strength materials. Boron is primarily used in chemical compounds, about half of all consumption globally, boron is used as an additive in glass fibers of boron-containing fiberglass for insulation and structural materials. The next leading use is in polymers and ceramics in high-strength, lightweight structural, borosilicate glass is desired for its greater strength and thermal shock resistance than ordinary soda lime glass. Boron compounds are used as fertilizers in agriculture and in sodium perborate bleaches, a small amount of boron is used as a dopant in semiconductors, and reagent intermediates in the synthesis of organic fine chemicals. A few boron-containing organic pharmaceuticals are used or are in study, natural boron is composed of two stable isotopes, one of which has a number of uses as a neutron-capturing agent. In biology, borates have low toxicity in mammals, but are toxic to arthropods and are used as insecticides. Boric acid is mildly antimicrobial, and several natural boron-containing organic antibiotics are known, small amounts of boron compounds play a strengthening role in the cell walls of all plants, making boron a necessary plant nutrient. Boron is involved in the metabolism of calcium in both plants and animals and it is considered an essential nutrient for humans, and boron deficiency is implicated in osteoporosis. The word boron was coined from borax, the mineral from which it was isolated, by analogy with carbon, marco Polo brought some glazes back to Italy in the 13th century. Agricola, around 1600, reports the use of borax as a flux in metallurgy, in 1777, boric acid was recognized in the hot springs near Florence, Italy, and became known as sal sedativum, with primarily medical uses. The rare mineral is called sassolite, which is found at Sasso, Sasso was the main source of European borax from 1827 to 1872, when American sources replaced it. Boron compounds were relatively rarely used until the late 1800s when Francis Marion Smiths Pacific Coast Borax Company first popularized and produced them in volume at low cost
20.
Silicon
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Silicon is a chemical element with symbol Si and atomic number 14. A hard and brittle crystalline solid with a metallic luster. It is a member of group 14 in the table, along with carbon above it and germanium, tin, lead. It is not very reactive, although more reactive than germanium, Silicon is the eighth most common element in the universe by mass, but very rarely occurs as the pure element in the Earths crust. It is most widely distributed in dusts, sands, planetoids, over 90% of the Earths crust is composed of silicate minerals, making silicon the second most abundant element in the Earths crust after oxygen. Most silicon is used commercially without being separated, and often with little processing of the natural minerals, such use includes industrial construction with clays, silica sand, and stone. Silicate is used in Portland cement for mortar and stucco, and mixed with sand and gravel to make concrete for walkways, foundations. Silicates are used in whiteware ceramics such as porcelain, and in traditional quartz-based soda-lime glass, Silicon compounds such as silicon carbide are used as abrasives and components of high-strength ceramics. Elemental silicon also has an impact on the modern world economy. Most free silicon is used in the refining, aluminium-casting. Silicon is the basis of the widely used synthetic polymers called silicones, Silicon is an essential element in biology, although only tiny traces are required by animals. However, various sea sponges and microorganisms, such as diatoms and radiolaria, silica is deposited in many plant tissues, such as in the bark and wood of Chrysobalanaceae and the silica cells and silicified trichomes of Cannabis sativa, horsetails and many grasses. Silicon is a solid at room temperature, with a point of 1,414 °C. Like water, it has a density in a liquid state than in a solid state and it expands when it freezes. With a relatively high conductivity of 149 W·m−1·K−1, silicon conducts heat well. In its crystalline form, pure silicon has a gray color, like germanium, silicon is rather strong, very brittle, and prone to chipping. Silicon, like carbon and germanium, crystallizes in a cubic crystal structure with a lattice spacing of 0.5430710 nm. The outer electron orbital of silicon, like that of carbon, has four valence electrons, the 1s, 2s, 2p and 3s subshells are completely filled while the 3p subshell contains two electrons out of a possible six
21.
Cobalt
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Cobalt is a chemical element with symbol Co and atomic number 27. Like nickel, cobalt is found in the Earths crust only in chemically combined form, the free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal. In 1735, such ores were found to be reducible to a new metal, today, some cobalt is produced specifically from various metallic-lustered ores, for example cobaltite, but the main source of the element is as a by-product of copper and nickel mining. The copper belt in the Democratic Republic of the Congo, Central African Republic, cobalt is primarily used in the preparation of magnetic, wear-resistant and high-strength alloys. The compounds, cobalt silicate and cobalt aluminate give a deep blue color to glass, ceramics, inks, paints. Cobalt occurs naturally as only one isotope, cobalt-59. Cobalt-60 is an important radioisotope, used as a radioactive tracer. Cobalt is the center of coenzymes called cobalamins, the most common example of which is vitamin B12. As such, it is a trace dietary mineral for all animals. Cobalt in inorganic form is also a micronutrient for bacteria, algae, cobalt is a ferromagnetic metal with a specific gravity of 8.9. The Curie temperature is 1,115 °C and the moment is 1. 6–1.7 Bohr magnetons per atom. Cobalt has a relative permeability two-thirds that of iron, metallic cobalt occurs as two crystallographic structures, hcp and fcc. The ideal transition temperature between the hcp and fcc structures is 450 °C, but in practice, the difference is so small that random intergrowth of the two is common. Cobalt is a weakly reducing metal that is protected from oxidation by an oxide film. It is attacked by halogens and sulfur, heating in oxygen produces Co3O4 which loses oxygen at 900 °C to give the monoxide CoO. The metal reacts with fluorine at 520 K to give CoF3, with chlorine, bromine and iodine and it does not react with hydrogen gas or nitrogen gas even when heated, but it does react with boron, carbon, phosphorus, arsenic and sulfur. At ordinary temperatures, it reacts slowly with mineral acids, and very slowly with moist, common oxidation states of cobalt include +2 and +3, although compounds with oxidation states ranging from −3 to +5 are also known. A common oxidation state for simple compounds is +2 and these salts form the pink-colored metal aquo complex 2+ in water
22.
Vanadium
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Vanadium is a chemical element with symbol V and atomic number 23. It is a hard, silvery grey, ductile, and malleable transition metal, the elemental metal is rarely found in nature, but once isolated artificially, the formation of an oxide layer stabilizes the free metal somewhat against further oxidation. Four years later, however, he was convinced by other scientists that erythronium was identical to chromium, both names were attributed to the wide range of colors found in vanadium compounds. Del Rios lead mineral was later renamed vanadinite for its vanadium content, in 1867 Henry Enfield Roscoe obtained the pure element. Vanadium occurs naturally in about 65 different minerals and in fossil fuel deposits and it is produced in China and Russia from steel smelter slag, other countries produce it either from the flue dust of heavy oil, or as a byproduct of uranium mining. It is mainly used to produce specialty steel alloys such as high-speed tool steels, the most important industrial vanadium compound, vanadium pentoxide, is used as a catalyst for the production of sulfuric acid. Large amounts of ions are found in a few organisms. The oxide and some salts of vanadium have moderate toxicity. Particularly in the ocean, vanadium is used by life forms as an active center of enzymes. Vanadium was discovered by Andrés Manuel del Río, a Spanish-Mexican mineralogist, Del Río extracted the element from a sample of Mexican brown lead ore, later named vanadinite. He found that its salts exhibit a variety of colors. Later, Del Río renamed the element erythronium because most of the salts turned red upon heating, Del Río accepted Collet-Descotils statement and retracted his claim. In 1831, the Swedish chemist Nils Gabriel Sefström rediscovered the element in a new oxide he found working with iron ores. Later that same year, Friedrich Wöhler confirmed del Ríos earlier work, Sefström chose a name beginning with V, which had not been assigned to any element yet. He called the element vanadium after Old Norse Vanadís, because of the many beautifully colored chemical compounds it produces, in 1831, the geologist George William Featherstonhaugh suggested that vanadium should be renamed rionium after del Río, but this suggestion was not followed. The isolation of vanadium metal proved difficult, in 1831, Berzelius reported the production of the metal, but Henry Enfield Roscoe showed that Berzelius had in fact produced the nitride, vanadium nitride. Roscoe eventually produced the metal in 1867 by reduction of chloride, VCl2. In 1927, pure vanadium was produced by reducing vanadium pentoxide with calcium, the first large-scale industrial use of vanadium was in the steel alloy chassis of the Ford Model T, inspired by French race cars
23.
Chemical compound
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A chemical compound is an entity consisting of two or more atoms, at least two from different elements, which associate via chemical bonds. Many chemical compounds have a numerical identifier assigned by the Chemical Abstracts Service. For example, water is composed of two atoms bonded to one oxygen atom, the chemical formula is H2O. A compound can be converted to a different chemical composition by interaction with a chemical compound via a chemical reaction. In this process, bonds between atoms are broken in both of the compounds, and then bonds are reformed so that new associations are made between atoms. Schematically, this reaction could be described as AB + CD → AC + BD, where A, B, C, and D are each unique atoms, and AB, CD, AC, and BD are each unique compounds. A chemical element bonded to a chemical element is not a chemical compound since only one element. Examples are the diatomic hydrogen and the polyatomic molecule sulfur. Chemical compounds have a unique and defined chemical structure held together in a spatial arrangement by chemical bonds. Pure chemical elements are not considered chemical compounds, failing the two or more atom requirement, though they often consist of molecules composed of multiple atoms. There is varying and sometimes inconsistent nomenclature differentiating substances, which include truly non-stoichiometric examples, from chemical compounds, other compounds regarded as chemically identical may have varying amounts of heavy or light isotopes of the constituent elements, which changes the ratio of elements by mass slightly. Characteristic properties of compounds include that elements in a compound are present in a definite proportion, for example, the molecule of the compound water is composed of hydrogen and oxygen in a ratio of 2,1. In addition, compounds have a set of properties. The physical and chemical properties of compounds differ from those of their constituent elements, however, mixtures can be created by mechanical means alone, but a compound can be created only by a chemical reaction. Some mixtures are so combined that they have some properties similar to compounds. Other examples of compound-like mixtures include intermetallic compounds and solutions of metals in a liquid form of ammonia. Compounds may be described using formulas in various formats, for compounds that exist as molecules, the formula for the molecular unit is shown. For polymeric materials, such as minerals and many metal oxides, the elements in a chemical formula are normally listed in a specific order, called the Hill system
24.
Protein
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Proteins are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, a linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide, short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides, or sometimes oligopeptides. The individual amino acid residues are bonded together by peptide bonds, the sequence of amino acid residues in a protein is defined by the sequence of a gene, which is encoded in the genetic code. In general, the code specifies 20 standard amino acids, however. Sometimes proteins have non-peptide groups attached, which can be called prosthetic groups or cofactors, proteins can also work together to achieve a particular function, and they often associate to form stable protein complexes. Once formed, proteins only exist for a period of time and are then degraded and recycled by the cells machinery through the process of protein turnover. A proteins lifespan is measured in terms of its half-life and covers a wide range and they can exist for minutes or years with an average lifespan of 1–2 days in mammalian cells. Abnormal and or misfolded proteins are degraded more rapidly due to being targeted for destruction or due to being unstable. Like other biological macromolecules such as polysaccharides and nucleic acids, proteins are essential parts of organisms, many proteins are enzymes that catalyse biochemical reactions and are vital to metabolism. Proteins also have structural or mechanical functions, such as actin and myosin in muscle and the proteins in the cytoskeleton, other proteins are important in cell signaling, immune responses, cell adhesion, and the cell cycle. In animals, proteins are needed in the diet to provide the essential amino acids that cannot be synthesized, digestion breaks the proteins down for use in the metabolism. Methods commonly used to study structure and function include immunohistochemistry, site-directed mutagenesis, X-ray crystallography, nuclear magnetic resonance. Most proteins consist of linear polymers built from series of up to 20 different L-α-amino acids, all proteinogenic amino acids possess common structural features, including an α-carbon to which an amino group, a carboxyl group, and a variable side chain are bonded. Only proline differs from this structure as it contains an unusual ring to the N-end amine group. The amino acids in a chain are linked by peptide bonds. Once linked in the chain, an individual amino acid is called a residue, and the linked series of carbon, nitrogen. The peptide bond has two forms that contribute some double-bond character and inhibit rotation around its axis, so that the alpha carbons are roughly coplanar
25.
DNA
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Deoxyribonucleic acid is a molecule that carries the genetic instructions used in the growth, development, functioning and reproduction of all known living organisms and many viruses. DNA and RNA are nucleic acids, alongside proteins, lipids and complex carbohydrates, most DNA molecules consist of two biopolymer strands coiled around each other to form a double helix. The two DNA strands are termed polynucleotides since they are composed of simpler units called nucleotides. Each nucleotide is composed of one of four nitrogen-containing nucleobases—cytosine, guanine, adenine, or thymine —a sugar called deoxyribose, and a phosphate group. The nucleotides are joined to one another in a chain by covalent bonds between the sugar of one nucleotide and the phosphate of the next, resulting in an alternating sugar-phosphate backbone. The nitrogenous bases of the two polynucleotide strands are bound together, according to base pairing rules, with hydrogen bonds to make double-stranded DNA. The total amount of related DNA base pairs on Earth is estimated at 5.0 x 1037, in comparison the total mass of the biosphere has been estimated to be as much as 4 trillion tons of carbon. The DNA backbone is resistant to cleavage, and both strands of the double-stranded structure store the same biological information and this information is replicated as and when the two strands separate. A large part of DNA is non-coding, meaning that these sections do not serve as patterns for protein sequences, the two strands of DNA run in opposite directions to each other and are thus antiparallel. Attached to each sugar is one of four types of nucleobases and it is the sequence of these four nucleobases along the backbone that encodes biological information. RNA strands are created using DNA strands as a template in a process called transcription, under the genetic code, these RNA strands are translated to specify the sequence of amino acids within proteins in a process called translation. Within eukaryotic cells DNA is organized into structures called chromosomes. During cell division these chromosomes are duplicated in the process of DNA replication, eukaryotic organisms store most of their DNA inside the cell nucleus and some of their DNA in organelles, such as mitochondria or chloroplasts. In contrast prokaryotes store their DNA only in the cytoplasm, within the eukaryotic chromosomes, chromatin proteins such as histones compact and organize DNA. These compact structures guide the interactions between DNA and other proteins, helping control which parts of the DNA are transcribed, DNA was first isolated by Friedrich Miescher in 1869. DNA is used by researchers as a tool to explore physical laws and theories, such as the ergodic theorem. The unique material properties of DNA have made it an attractive molecule for material scientists and engineers interested in micro-, among notable advances in this field are DNA origami and DNA-based hybrid materials. DNA is a polymer made from repeating units called nucleotides
26.
Chlorophyll
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Chlorophyll is any of several closely related green pigments found in cyanobacteria and the chloroplasts of algae and plants. Its name is derived from the Greek words χλωρός, chloros and φύλλον, chlorophyll is essential in photosynthesis, allowing plants to absorb energy from light. Chlorophyll absorbs light most strongly in the portion of the electromagnetic spectrum. Conversely, it is a poor absorber of green and near-green portions of the spectrum, chlorophyll molecules are specifically arranged in and around photosystems that are embedded in the thylakoid membranes of chloroplasts. Two types of chlorophyll exist in the photosystems of green plants, chlorophyll was first isolated and named by Joseph Bienaimé Caventou and Pierre Joseph Pelletier in 1817. Chlorophyll is vital for photosynthesis, which plants to absorb energy from light. Chlorophyll molecules are arranged in and around photosystems that are embedded in the thylakoid membranes of chloroplasts. In these complexes, chlorophyll serves two primary functions, the two currently accepted photosystem units are photosystem II and photosystem I, which have their own distinct reaction centres, named P680 and P700, respectively. These centres are named after the wavelength of their red-peak absorption maximum, the identity, function and spectral properties of the types of chlorophyll in each photosystem are distinct and determined by each other and the protein structure surrounding them. Once extracted from the protein into a solvent, these chlorophyll pigments can be separated into chlorophyll a, the function of the reaction center of chlorophyll is to absorb light energy and transfer it to other parts of the photosystem. The absorbed energy of the photon is transferred to an electron in a process called charge separation, the removal of the electron from the chlorophyll is an oxidation reaction. The chlorophyll donates the high energy electron to a series of molecular intermediates called a transport chain. The charged reaction center of chlorophyll is reduced back to its ground state by accepting an electron stripped from water. The electron that reduces P680+ ultimately comes from the oxidation of water into O2 and this reaction is how photosynthetic organisms such as plants produce O2 gas, and is the source for practically all the O2 in Earths atmosphere. Electron transfer reactions in the membranes are complex, however. NADPH is an agent used to reduce CO2 into sugars as well as other biosynthetic reactions. Thus, the other chlorophylls in the photosystem and antenna pigment proteins all cooperatively absorb, besides chlorophyll a, there are other pigments, called accessory pigments, which occur in these pigment–protein antenna complexes. Chlorophyll is a pigment, which is structurally similar to
27.
Legume
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A legume is a plant or its fruit or seed in the family Fabaceae. Legumes are grown agriculturally, primarily for their grain seed called pulse, for forage and silage. Well-known legumes include alfalfa, clover, peas, beans, lentils, lupin bean, mesquite, carob, soybeans, peanuts, Fabaceae is the most common family found in tropical rainforests and in dry forests in the Americas and Africa. A legume fruit is a dry fruit that develops from a simple carpel. A common name for type of fruit is a pod, although the term pod is also applied to a number of other fruit types, such as that of vanilla. Legumes are notable in that most of them have symbiotic nitrogen-fixing bacteria in structures called root nodules, for that reason, they play a key role in crop rotation. The term pulse, as used by the United Nations Food and this excludes green beans and green peas, which are considered vegetable crops. Also excluded are seeds that are grown for oil extraction. However, in usage, these distinctions are not always clearly made. Some Fabaceae, such as Scotch broom and other Genisteae, are leguminous but are not called legumes by farmers. Farmed legumes can belong to many classes, including forage, grain, blooms, pharmaceutical/industrial, fallow/green manure. Most commercially farmed species fill two or more roles simultaneously, depending upon their degree of maturity when harvested, grain legumes are cultivated for their seeds. The seeds are used for human and animal consumption or for the production of oils for industrial uses, grain legumes include beans, lentils, lupins, peas, and peanuts. Like other plant-based foods, pulses contain no cholesterol and little fat or sodium, Legumes are also an excellent source of resistant starch which is broken down by bacteria in the large intestine to produce short-chain fatty acids used by intestinal cells for food energy. Preliminary studies in humans include the potential for regular consumption of legumes in a diet to affect metabolic syndrome. There is evidence that a portion of pulses in a diet may lower blood pressure and reduce LDL cholesterol levels. Some, like alfalfa, clover, vetch, stylo, or Arachis, are sown in pasture, other forage legumes such as Leucaena or Albizia are woody shrub or tree species that are either broken down by livestock or regularly cut by humans to provide livestock feed. Legume species grown for their flowers include lupins, which are farmed commercially for their blooms as well as being popular in gardens worldwide, industrially farmed legumes include Indigofera and Acacia species, which are cultivated for dye and natural gum production, respectively
28.
Adenosine triphosphate
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Adenosine triphosphate is a nucleotide, also called a nucleoside triphosphate, is a small molecule used in cells as a coenzyme. It is often referred to as the unit of currency of intracellular energy transfer. ATP transports chemical energy within cells for metabolism, most cellular functions need energy in order to be carried out, synthesis of proteins, synthesis of membranes, movement of the cell, cellular division, transport of various solutes etc. The ATP is the molecule that carries energy to the place where the energy is needed, when ATP breaks into ADP and Pi, the breakdown of the last covalent link of phosphate liberates energy that is used in reactions where it is needed. Substrate-level phosphorylation, oxidative phosphorylation in cellular respiration, and photophosphorylation in photosynthesis are three mechanisms of ATP biosynthesis. Metabolic processes that use ATP as an energy source convert it back into its precursors, ATP is therefore continuously recycled in organisms, the human body, which on average contains only 250 grams of ATP, turns over its own body weight equivalent in ATP each day. ATP is used as a substrate in signal transduction pathways by kinases that phosphorylate proteins and it is also used by adenylate cyclase, which uses ATP to produce the second messenger molecule cyclic AMP. The ratio between ATP and AMP is used as a way for a cell to sense how much energy is available and control the metabolic pathways that produce and consume ATP. Apart from its roles in signaling and energy metabolism, ATP is also incorporated into nucleic acids by polymerases in the process of transcription, ATP is the neurotransmitter believed to signal the sense of taste. The structure of this consists of a purine base attached by the 9′ nitrogen atom to the 1′ carbon atom of a pentose sugar. Three phosphate groups are attached at the 5′ carbon atom of the pentose sugar and it is the addition and removal of these phosphate groups that inter-convert ATP, ADP and AMP. When ATP is used in DNA synthesis, the sugar is first converted to deoxyribose by ribonucleotide reductase. ATP was discovered in 1929 by Karl Lohmann, and independently by Cyrus Fiske and Yellapragada Subbarow of Harvard Medical School and it was proposed to be the intermediary molecule between energy-yielding and energy-requiring reactions in cells by Fritz Albert Lipmann in 1941. It was first artificially synthesized by Alexander Todd in 1948, ATP consists of adenosine – composed of an adenine ring and a ribose sugar – and three phosphate groups. The phosphoryl groups, starting with the group closest to the ribose, are referred to as the alpha, beta, consequently, it is closely related to the adenosine nucleotide, a monomer of RNA. ATP is highly soluble in water and is stable in solutions between pH6.8 and 7.4, but is rapidly hydrolysed at extreme pH. Consequently, ATP is best stored as an anhydrous salt, ATP is an unstable molecule in unbuffered water, in which it hydrolyses to ADP and phosphate. This is because the strength of the bonds between the groups in ATP is less than the strength of the hydrogen bonds, between its products, and water
29.
Parts-per notation
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In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e. g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they are pure numbers with no associated units of measurement, commonly used are ppm, ppb, ppt and ppq. Parts-per notation is often used describing dilute solutions in chemistry, for instance, the unit “1 ppm” can be used for a mass fraction if a water-borne pollutant is present at one-millionth of a gram per gram of sample solution. When working with aqueous solutions, it is common to assume that the density of water is 1.00 g/mL, therefore, it is common to equate 1 kilogram of water with 1 L of water. Consequently,1 ppm corresponds to 1 mg/L and 1 ppb corresponds to 1 μg/L, similarly, parts-per notation is used also in physics and engineering to express the value of various proportional phenomena. For instance, a metal alloy might expand 1.2 micrometers per meter of length for every degree Celsius. For instance, the accuracy of distance measurements when using a laser rangefinder might be 1 millimeter per kilometer of distance, this could be expressed as “Accuracy =1 ppm. ”Parts-per notations are all dimensionless quantities, in mathematical expressions. In fractions like “2 nanometers per meter” so the quotients are pure-number coefficients with positive values less than 1, when parts-per notations, including the percent symbol, are used in regular prose, they are still pure-number dimensionless quantities. However, they take the literal “parts per” meaning of a comparative ratio. Parts-per notations may be expressed in terms of any unit of the same measure, in nuclear magnetic resonance spectroscopy, chemical shift is usually expressed in ppm. It represents the difference of a frequency in parts per million from the reference frequency. The reference frequency depends on the magnetic field and the element being measured. It is usually expressed in MHz, typical chemical shifts are rarely more than a few hundred Hz from the reference frequency, so chemical shifts are conveniently expressed in ppm. Parts-per notation gives a quantity that does not depend on the instruments field strength. One part per hundred is generally represented by the percent symbol and denotes one part per 100 parts, one part in 102, and this is equivalent to approximately one drop of water diluted into 5 milliliters or about fifteen minutes out of one day. One part per thousand should generally be spelled out in full and it may also be denoted by the millage symbol. Note however, that specific disciplines such as oceanography, as well as educational exercises, one part per thousand denotes one part per 1000 parts, one part in 103, and a value of 1 × 10−3. This is equivalent to one drop of water diluted into 50 milliliters or about one, one part per ten thousand is denoted by the permyriad symbol
30.
Urea
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Urea, also known as carbamide, is an organic compound with the chemical formula CO2. This amide has two groups joined by a carbonyl functional group. Urea serves an important role in the metabolism of nitrogen-containing compounds by animals and is the main nitrogen-containing substance in the urine of mammals and it is a colorless, odorless solid, highly soluble in water, and practically non-toxic. Dissolved in water, it is neither acidic nor alkaline, the body uses it in many processes, most notably nitrogen excretion. The liver forms it by combining two molecules with a carbon dioxide molecule in the urea cycle. Urea is widely used in fertilizers as a source of nitrogen and is an important raw material for the chemical industry, Friedrich Wöhlers discovery in 1828 that urea can be produced from inorganic starting materials was an important conceptual milestone in chemistry. More than 90% of world production of urea is destined for use as a nitrogen-release fertilizer. Urea has the highest nitrogen content of all solid nitrogenous fertilizers in common use, therefore, it has the lowest transportation costs per unit of nitrogen nutrient. The standard crop-nutrient rating of urea is 46-0-0, many soil bacteria possess the enzyme urease, which catalyzes conversion of urea to ammonia or ammonium ion and bicarbonate ion. Thus urea fertilizers rapidly transform to the form in soils. Ammonium and nitrate are readily absorbed by plants, and are the dominant sources of nitrogen for plant growth, Urea is also used in many multi-component solid fertilizer formulations. Urea is highly soluble in water and is also very suitable for use in fertilizer solutions. For fertilizer use, granules are preferred over prills because of their particle size distribution. The most common impurity of synthetic urea is biuret, which impairs plant growth, Urea is usually spread at rates of between 40 and 300 kg/ha but rates vary. Smaller applications incur lower losses due to leaching, during summer, urea is often spread just before or during rain to minimize losses from volatilization. Because of the nitrogen concentration in urea, it is very important to achieve an even spread. The application equipment must be calibrated and properly used. Drilling must not occur on contact with or close to seed, Urea dissolves in water for application as a spray or through irrigation systems
31.
Ammonium nitrate
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Ammonium nitrate is a chemical compound, the nitrate salt of the ammonium cation. It has the chemical formula NH4NO3, simplified to N2H4O3 and it is a white crystal solid and is highly soluble in water. It is predominantly used in agriculture as a high-nitrogen fertilizer and its other major use is as a component of explosive mixtures used in mining, quarrying, and civil construction. It is the constituent of ANFO, a popular industrial explosive which accounts for 80% of explosives used in North America. Many countries are phasing out its use in consumer applications due to concerns over its potential for misuse, ammonium nitrate was mined there in the past, but virtually 100% of the chemical now used is synthetic. This reaction is violent owing to its exothermic nature. After the solution is formed, typically at about 83% concentration, the AN melt is then made into prills or small beads in a spray tower, or into granules by spraying and tumbling in a rotating drum. The prills or granules may be dried, cooled. These prills or granules are the typical AN products in commerce, the ammonia required for this process is obtained by the Haber process from nitrogen and hydrogen. Ammonia produced by the Haber process is oxidized to nitric acid by the Ostwald process, transformations of the crystal states due to changing conditions affect the physical properties of ammonium nitrate. Ammonium nitrate is an important fertilizer with the NPK rating 34-0-0 and it is less concentrated than urea, giving ammonium nitrate a slight transportation disadvantage. Ammonium nitrates advantage over urea is that it is more stable, during warm weather it is best to apply urea soon before rain is expected or to cover it with soil to minimize nitrogen loss. ANFO is a mixture of 94% ammonium nitrate and 6% fuel oil used as a bulk industrial explosive. Ammonium nitrate-based explosives were used in the Oklahoma City Bombing in 1995 and 2011 Delhi bombings, the 2013 Hyderabad blasts, due to these bans, Potassium chlorate — the stuff that makes matches catch fire — has surpassed fertilizer as the explosive of choice for insurgents. Ammonium nitrate is used in instant cold packs, as its dissolution in water is highly endothermic. Health and safety data are shown on the safety data available from suppliers. Heating or any ignition source may cause violent combustion or explosion, ammonium nitrate reacts with combustible and reducing materials as it is a strong oxidant. Although it is used for fertilizer, it can be used for explosives
32.
Water of crystallization
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In chemistry, water of crystallization or water of hydration or crystallization water is water that occurs inside crystals. Water is often incorporated in the formation of crystals from aqueous solutions, in some contexts, water of crystallization is the total weight of water in a substance at a given temperature and is mostly present in a definite ratio. Classically, water of crystallization refers to water that is found in the framework of a metal complex or a salt. Upon crystallization from water or moist solvents, many compounds incorporate water molecules in their crystalline frameworks, water of crystallization can generally be removed by heating a sample but the crystalline properties are often lost. For example, in the case of chloride, the dihydrate is unstable at room temperature. Compared to inorganic salts, proteins crystallize with large amounts of water in the crystal lattice, the water content of 50% is not uncommon for proteins. For example Calcium chloride, CaCl2·2H2O hydrated compoundn A hydrate with coordinated water, for example Zinc chloride, ZnCl24 Both notations can be combined as for example in copper sulfate, SO4·H2O A salt with associated water of crystallization is known as a hydrate. The structure of hydrates can be elaborate, because of the existence of hydrogen bonds that define polymeric structures. Historically, the structures of many hydrates were unknown, and the dot in the formula of a hydrate was employed to specify the composition without indicating how the water is bound, for example, an aqueous solution prepared from CuSO4•5H2O and anhydrous CuSO4 behave identically. Therefore, knowledge of the degree of hydration is important only for determining the equivalent weight, in some cases, the degree of hydration can be critical to the resulting chemical properties. For example, anhydrous RhCl3 is not soluble in water and is useless in organometallic chemistry whereas RhCl3•3H2O is versatile. Similarly, hydrated AlCl3 is a poor Lewis acid and thus inactive as a catalyst for Friedel-Crafts reactions, samples of AlCl3 must therefore be protected from atmospheric moisture to preclude the formation of hydrates. Crystals of the aforementioned hydrated copper sulfate consist of 2+ centers linked to SO42− ions, copper is surrounded by six oxygen atoms, provided by two different sulfate groups and four molecules of water. A fifth water resides elsewhere in the framework but does not bind directly to copper, the cobalt chloride mentioned above occurs as 2+ and Cl−. In tin chloride, each Sn center is pyramidal being bound to two chloride ions and one water, the second water in the formula unit is hydrogen-bonded to the chloride and to the coordinated water molecule. Water of crystallization is stabilized by electrostatic attractions, consequently hydrates are common for salts that contain +2, in some cases, the majority of the weight of a compound arises from water. Glaubers salt, Na2SO410, is a crystalline solid with greater than 50% water by weight. Consider the case of nickel chloride hexahydrate and this species has the formula NiCl26
33.
Monocalcium phosphate
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Monocalcium phosphate is an inorganic compound with the chemical formula Ca2. It is commonly found as the monohydrate, Ca2·H2O and they are used mainly as superphosphate fertilizers and are also popular leavening agents. Using phosphoric acid, fluorapatite is converted to Ca2, Ca53F +7 H3PO4 →5 Ca2 + HF This solid is called triple superphosphate, several million tons are produced annually for use as fertilizers. Residual HF typically reacts with silicate minerals co-mingled with the ores to produce hydrofluorosilicic acid. The majority of the acid is converted to aluminium fluoride. These materials are central to the conversion of aluminium ore into aluminium metal, when sulfuric acid is used, the product contains phosphogypsum and is called single superphosphate. Calcium dihydrogen phosphate is used in the industry as a leavening agent. Because it is acidic, when combined with an ingredient, commonly sodium bicarbonate or potassium bicarbonate, it reacts to produce carbon dioxide. Outward pressure of the carbon dioxide gas causes the rising effect, AMCP and MCP are fast acting, releasing most carbon dioxide within minutes of mixing. It is popularly used in pancake mixes, in double acting baking powders, MCP is often combined with the slow acting acid sodium acid pyrophosphate. Dicalcium phosphate Havlin, J. L. J. D. Beaton, 7th edn. Pearson Prentice Hall, N. J
34.
Phosphogypsum
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Phosphogypsum refers to the gypsum formed as a by-product of the production of fertilizer from phosphate rock. It is mainly composed of gypsum, although gypsum is a widely used material in the construction industry, phosphogypsum is usually not used, but is stored indefinitely because of its weak radioactivity. Marine-deposited phosphate typically has a level of radioactivity than igneous phosphate deposits. Phosphogypsum also can contain levels of cadmium. The United States Environmental Protection Agency has banned most applications of phosphogypsum having a 226Ra concentration of greater than 10 picocurie/gram, as a result, phosphogypsum which exceeds this limit is stored in large stacks. Central Florida has a quantity of phosphate deposits, particularly in the Bone Valley region. However, the phosphate ore from central Florida is weakly radioactive, and as such. As a result, there are about 1 billion tons of phosphogypsum stacked in 25 stacks in Florida and about 30 million new tons are generated each year
35.
Sulfate
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The sulfate or sulphate ion is a polyatomic anion with the empirical formula SO2−4. Sulfate is the spelling recommended by IUPAC, but sulphate is used in British English, salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life, sulfates are salts of sulfuric acid and many are prepared from that acid. The sulfate anion consists of a sulfur atom surrounded by four equivalent oxygen atoms in a tetrahedral arrangement. The symmetry is the same as that of methane, the sulfur atom is in the +6 oxidation state while the four oxygen atoms are each in the state. The sulfate ion carries a charge of −2 and it is the conjugate base of the bisulfate ion, HSO−4. Organic sulfate esters, such as sulfate, are covalent compounds. The tetrahedral molecular geometry of the ion is as predicted by VSEPR theory. Later, Linus Pauling used valence bond theory to propose that the most significant resonance canonicals had two pi bonds involving d orbitals and his reasoning was that the charge on sulfur was thus reduced, in accordance with his principle of electroneutrality. The S−O bond length of 149 pm is shorter than the bond lengths in sulfuric acid of 157 pm for S−OH, the double bonding was taken by Pauling to account for the shortness of the S−O bond. Paulings use of d orbitals provoked a debate on the importance of π bonding. The outcome was a consensus that d orbitals play a role. A widely accepted description involving pπ – dπ bonding was initially proposed by D. W. J. Cruickshank, in this model, fully occupied p orbitals on oxygen overlap with empty sulfur d orbitals. However, in description, despite there being some π character to the S−O bonds. For sulfuric acid, computational analysis confirms a positive charge on sulfur. Therefore, the representation with four single bonds is the optimal Lewis structure rather than the one with two double bonds, in this model, the structure obeys the octet rule and the charge distribution is in agreement with the electronegativity of the atoms. However, the representation of Pauling for sulfate and other main group compounds with oxygen is still a common way of representing the bonding in many textbooks. On the other hand, in the structure with an ionic bond, exceptions include calcium sulfate, strontium sulfate, lead sulfate, and barium sulfate, which are poorly soluble
36.
Ammonium dihydrogen phosphate
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Monoammonium phosphate is often used in the blending of dry agricultural fertilizers. It supplies soil with the nitrogen and phosphorus in a form usable by plants. The compound is also a component of the ABC powder in some dry chemical fire extinguishers and this substance is also supplied in an emerald green, amethyst, or aquamarine crystal growing box kit for children. As a result of its crystal structure, this material has negative uniaxial optical symmetry with typical refractive indices no =1.522. ADP crystals are piezoelectric, a property required in some active sonar transducers, in the 1950s ADP crystals largely replaced the quartz and Rochelle salt crystals in transducers because they are easier to work than Quartz and, unlike Rochelle Salt, are not deliquescent. MAP is mainly used as a fertilizer, but also as dry fire extinguisher, however MAP is also used in childrens crystal growing experiment uses
37.
Diammonium phosphate
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Diammonium phosphate is one of a series of water-soluble ammonium phosphate salts that can be produced when ammonia reacts with phosphoric acid. Decomposes to ammonia and monoammonium phosphate at around 70°C, at 155°C, DAP emits phosphorus oxides, nitrogen oxides and ammonia. DAP is used as a fertilizer, when applied as plant food, it temporarily increases the soil pH, but over a long term the treated ground becomes more acidic than before upon nitrification of the ammonium. It is incompatible with alkaline chemicals because its ammonium ion is likely to convert to ammonia in a high-pH environment. The average pH in solution is 7. 5–8, DAP can be used as a fire retardant. It lowers the temperature of the material, decreases maximum weight loss rates. It is the largest component of some popular commercial firefighting products, international Chemical Safety Card 0217 Diammonium phosphate fertilizer manufacturing process flowsheet
38.
Chelation
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Chelation is a type of bonding of ions and molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a ligand and a single central atom. Usually these ligands are organic compounds, and are called chelants, chelators, chelating agents, the chelate effect is the enhanced affinity of chelating ligands for a metal ion compared to the affinity of a collection of similar nonchelating ligands for the same metal. Consider the two equilibria, in solution, between the copper ion, Cu2+ and ethylenediamine on the one hand and methylamine, MeNH2 on the other. In the bidentate ligand ethylenediamine forms a complex with the copper ion. Chelation results in the formation of a five-membered CuC2N2 ring, the thermodynamic approach to describing the chelate effect considers the equilibrium constant for the reaction, the larger the equilibrium constant, the higher the concentration of the complex. Electrical charges have been omitted for simplicity of notation, the square brackets indicate concentration, and the subscripts to the stability constants, β, indicate the stoichiometry of the complex. Δ H ⊖ is the enthalpy change of the reaction. Since the enthalpy should be approximately the same for the two reactions, the difference between the two stability constants is due to the effects of entropy. In equation there are two particles on the left and one on the right, whereas in equation there are three particles on the left and one on the right. This difference means that less entropy of disorder is lost when the complex is formed than when the complex with monodentate ligands is formed. This is one of the factors contributing to the entropy difference, other factors include solvation changes and ring formation. Some experimental data to illustrate the effect are shown in the following table, other explanations, including that of Schwarzenbach, are discussed in Greenwood and Earnshaw. Numerous biomolecules exhibit the ability to dissolve certain metal cations, thus, proteins, polysaccharides, and polynucleic acids are excellent polydentate ligands for many metal ions. Organic compounds such as the amino acids glutamic acid and histidine, organic diacids such as malate, in addition to these adventitious chelators, several biomolecules are specifically produced to bind certain metals. Virtually all metalloenzymes feature metals that are chelated, usually to peptides or cofactors, such chelating agents include the porphyrin rings in hemoglobin and chlorophyll. Many microbial species produce pigments that serve as chelating agents. For example, species of Pseudomonas are known to secrete pyochelin, enterobactin, produced by E. coli, is the strongest chelating agent known
39.
Sugar beet
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Sugar beet is the Altissima Group of cultivars of the common beet. It is a plant whose root contains a concentration of sucrose. Sugar beets and other cultivars, such as beetroot and chard, are members of Beta vulgaris subsp. Vulgaris and share a common ancestor, the Sea beet. In 2013, Russia, France, the United States, Germany, however, in 2010–2011, North America, Western Europe, and Eastern Europe did not produce enough sugar from sugar beets to meet overall demand for sugar, and were all net importers of sugar. The US harvested 1,004,600 acres of beets in 2008. In 2009, sugar accounted for 20% of the worlds sugar production. The sugar beet has a conical, white, fleshy root with a flat crown, the plant consists of the root and a rosette of leaves. Sugar is formed by photosynthesis in the leaves, and is stored in the root. The root of the beet contains 75% water, about 20% sugar, Sugar is the primary value of sugar beet as a cash crop. The pulp, insoluble in water and mainly composed of cellulose, hemicellulose, lignin, the byproducts of the sugar beet crop, such as pulp and molasses, add another 10% to the value of the harvest. Sugar beets grow exclusively in the zone, in contrast to sugarcane. The average weight of sugar beet ranges between 0.5 and 1 kg, Sugar beet foliage has a rich, brilliant green color and grows to a height of about 35 cm. The leaves are numerous and broad and grow in a tuft from the crown of the beet, modern sugar beets date back to mid-18th century Silesia where the king of Prussia subsidised experiments aimed at processes for sugar extraction. In 1747 Andreas Marggraf isolated sugar from beetroots and found them at concentrations of 1. 3–1. 6% and he also demonstrated that sugar could be extracted from beets that was the same as that produced from sugarcane. His student, Franz Karl Achard, evaluated 23 varieties of mangelwurzel for sugar content and selected a strain from Halberstadt in modern-day Saxony-Anhalt. Moritz Baron von Koppy and his son further selected from this strain for white, the selection was named Weiße Schlesische Zuckerrübe, meaning white Silesian sugar beet, and boasted about a 6% sugar content. This selection is the progenitor of all modern sugar beets, a royal decree led to the first factory devoted to sugar extraction from beetroots being opened in Kunern, Silesia in 1801
40.
Brazil
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Brazil, officially the Federative Republic of Brazil, is the largest country in both South America and Latin America. As the worlds fifth-largest country by area and population, it is the largest country to have Portuguese as an official language. Its Amazon River basin includes a vast tropical forest, home to wildlife, a variety of ecological systems. This unique environmental heritage makes Brazil one of 17 megadiverse countries, Brazil was inhabited by numerous tribal nations prior to the landing in 1500 of explorer Pedro Álvares Cabral, who claimed the area for the Portuguese Empire. Brazil remained a Portuguese colony until 1808, when the capital of the empire was transferred from Lisbon to Rio de Janeiro, in 1815, the colony was elevated to the rank of kingdom upon the formation of the United Kingdom of Portugal, Brazil and the Algarves. Independence was achieved in 1822 with the creation of the Empire of Brazil, a state governed under a constitutional monarchy. The ratification of the first constitution in 1824 led to the formation of a bicameral legislature, the country became a presidential republic in 1889 following a military coup détat. An authoritarian military junta came to power in 1964 and ruled until 1985, Brazils current constitution, formulated in 1988, defines it as a democratic federal republic. The federation is composed of the union of the Federal District, the 26 states, Brazils economy is the worlds ninth-largest by nominal GDP and seventh-largest by GDP as of 2015. A member of the BRICS group, Brazil until 2010 had one of the worlds fastest growing economies, with its economic reforms giving the country new international recognition. Brazils national development bank plays an important role for the economic growth. Brazil is a member of the United Nations, the G20, BRICS, Unasul, Mercosul, Organization of American States, Organization of Ibero-American States, CPLP. Brazil is a power in Latin America and a middle power in international affairs. One of the worlds major breadbaskets, Brazil has been the largest producer of coffee for the last 150 years and it is likely that the word Brazil comes from the Portuguese word for brazilwood, a tree that once grew plentifully along the Brazilian coast. In Portuguese, brazilwood is called pau-brasil, with the word brasil commonly given the etymology red like an ember, formed from Latin brasa and the suffix -il. As brazilwood produces a red dye, it was highly valued by the European cloth industry and was the earliest commercially exploited product from Brazil. The popular appellation eclipsed and eventually supplanted the official Portuguese name, early sailors sometimes also called it the Land of Parrots. In the Guarani language, a language of Paraguay, Brazil is called Pindorama
41.
Turkey
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Turkey, officially the Republic of Turkey, is a transcontinental country in Eurasia, mainly in Anatolia in Western Asia, with a smaller portion on the Balkan peninsula in Southeast Europe. Turkey is a democratic, secular, unitary, parliamentary republic with a cultural heritage. The country is encircled by seas on three sides, the Aegean Sea is to the west, the Black Sea to the north, and the Mediterranean Sea to the south. The Bosphorus, the Sea of Marmara, and the Dardanelles, Ankara is the capital while Istanbul is the countrys largest city and main cultural and commercial centre. Approximately 70-80% of the countrys citizens identify themselves as ethnic Turks, other ethnic groups include legally recognised and unrecognised minorities. Kurds are the largest ethnic minority group, making up approximately 20% of the population, the area of Turkey has been inhabited since the Paleolithic by various ancient Anatolian civilisations, as well as Assyrians, Greeks, Thracians, Phrygians, Urartians and Armenians. After Alexander the Greats conquest, the area was Hellenized, a process continued under the Roman Empire. The Seljuk Sultanate of Rûm ruled Anatolia until the Mongol invasion in 1243, the empire reached the peak of its power in the 16th century, especially during the reign of Suleiman the Magnificent. During the war, the Ottoman government committed genocides against its Armenian, Assyrian, following the war, the conglomeration of territories and peoples that formerly comprised the Ottoman Empire was partitioned into several new states. Turkey is a member of the UN, an early member of NATO. Turkeys growing economy and diplomatic initiatives have led to its recognition as a regional power while her location has given it geopolitical, the name of Turkey is based on the ethnonym Türk. The first recorded use of the term Türk or Türük as an autonym is contained in the Old Turkic inscriptions of the Göktürks of Central Asia, the English name Turkey first appeared in the late 14th century and is derived from Medieval Latin Turchia. Similarly, the medieval Khazar Empire, a Turkic state on the shores of the Black. The medieval Arabs referred to the Mamluk Sultanate as al-Dawla al-Turkiyya, the Ottoman Empire was sometimes referred to as Turkey or the Turkish Empire among its European contemporaries. The Anatolian peninsula, comprising most of modern Turkey, is one of the oldest permanently settled regions in the world, various ancient Anatolian populations have lived in Anatolia, from at least the Neolithic period until the Hellenistic period. Many of these peoples spoke the Anatolian languages, a branch of the larger Indo-European language family, in fact, given the antiquity of the Indo-European Hittite and Luwian languages, some scholars have proposed Anatolia as the hypothetical centre from which the Indo-European languages radiated. The European part of Turkey, called Eastern Thrace, has also been inhabited since at least forty years ago. It is the largest and best-preserved Neolithic site found to date, the settlement of Troy started in the Neolithic Age and continued into the Iron Age
42.
Mexico
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Mexico, officially the United Mexican States, is a federal republic in the southern half of North America. It is bordered to the north by the United States, to the south and west by the Pacific Ocean, to the southeast by Guatemala, Belize, and the Caribbean Sea, and to the east by the Gulf of Mexico. Covering almost two million square kilometers, Mexico is the sixth largest country in the Americas by total area, Mexico is a federation comprising 31 states and a federal district that is also its capital and most populous city. Other metropolises include Guadalajara, Monterrey, Puebla, Toluca, Tijuana, pre-Columbian Mexico was home to many advanced Mesoamerican civilizations, such as the Olmec, Toltec, Teotihuacan, Zapotec, Maya and Aztec before first contact with Europeans. In 1521, the Spanish Empire conquered and colonized the territory from its base in Mexico-Tenochtitlan, Three centuries later, this territory became Mexico following recognition in 1821 after the colonys Mexican War of Independence. The tumultuous post-independence period was characterized by instability and many political changes. The Mexican–American War led to the cession of the extensive northern borderlands, one-third of its territory. The Pastry War, the Franco-Mexican War, a civil war, the dictatorship was overthrown in the Mexican Revolution of 1910, which culminated with the promulgation of the 1917 Constitution and the emergence of the countrys current political system. Mexico has the fifteenth largest nominal GDP and the eleventh largest by purchasing power parity, the Mexican economy is strongly linked to those of its North American Free Trade Agreement partners, especially the United States. Mexico was the first Latin American member of the Organisation for Economic Co-operation and Development and it is classified as an upper-middle income country by the World Bank and a newly industrialized country by several analysts. By 2050, Mexico could become the fifth or seventh largest economy. The country is considered both a power and middle power, and is often identified as an emerging global power. Due to its culture and history, Mexico ranks first in the Americas. Mexico is a country, ranking fourth in the world by biodiversity. In 2015 it was the 9th most visited country in the world, Mexico is a member of the United Nations, the World Trade Organization, the G8+5, the G20, the Uniting for Consensus and the Pacific Alliance. Mēxihco is the Nahuatl term for the heartland of the Aztec Empire, namely, the Valley of Mexico, and its people, the Mexica and this became the future State of Mexico as a division of New Spain prior to independence. It is generally considered to be a toponym for the valley became the primary ethnonym for the Aztec Triple Alliance as a result. After New Spain won independence from Spain, representatives decided to name the new country after its capital and this was founded in 1524 on top of the ancient Mexica capital of Mexico-Tenochtitlan
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This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Lawes, Sir John Bennet". Encyclopædia Britannica (11th ed.). Cambridge University Press.
This article incorporates text from a publication now in the 
